Field of the Invention
The present invention relates to a return spring common structure of an automatic transmission, and more particularly, to a return spring common structure of an automatic transmission with a reduced weight and improved assembly performance.
Description of Related Art
Generally, an automatic transmission is an apparatus which automatically performs a shift operation of shifting a torque transferred from an engine to be transferred to a driving wheel depending on a shift pattern and is configured to include a torque converter transferring a driving force of the engine to an input shaft of the transmission, a planetary gear shifting the driving force of the engine depending on a driving state of a vehicle, and a clutch and a brake controlling the driving force of the engine transferred to the planetary gear.
In particular, as the clutch included in the automatic transmission, a plurality of plates and a multi-plate clutch with which a plurality of discs are rubbed have been mainly used.
Transmission oil is injected into an oil chamber and thus a piston connected to the oil chamber presses the plurality of plates to rub the plate against the disc, power is transferred between a rotating element connected to the plate and a rotating element connected to the disc, and the transmission oil is discharged from the oil chamber to remove a force of the piston pressing the plate and cut off power between the two rotating elements.
In this case, the piston returns to a position before being pressed by the transmission oil by an elastic force of the return spring.
However, as the automatic transmission is multi-staged, the return spring and a snap ring fixing the return spring are many equipped in the automatic transmission. Therefore, the multiple return springs and snap rings fixing the return spring lead to an increase in weight of the automatic transmission and reduce assembly convenience.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.